Everything that surrounds us is matter. books, tables, trees, water, air… All of them are matter. However, matter needs to have mass and takes up space. Therefore, sound, light or our thoughts are not made up of matter.
Matter has general properties, such as mass and volume, and other specific properties like density.
Mass
Is the amount of matter in an object. Mass is measured in kilograms (kg) or grams (g). We use different types of scales to measure mass, like electronic scales.
Volume
Is the amount of space that an object occupies. Volume is measured in litres (l) or millilitres (ml). Cubic centimetres can also be used to measure volume. The volume of liquids is measured in measuring cylinders. Regular-shaped solids’ volume is calculated with mathematical formulas, while the volume of irregular-shaped solids is calculated by the water displacement method: when a solid is placed in a liquid, the liquid level rises.
Density
It is the concentration of matter in a particular volume. We calculate it by dividing its mass by its volume. Depending on their density, objects can sink or float when placed in a liquid. When the density of an object is higher than the density of the liquid, the object sinks.
We can find matter in three different states:
Solid
State of matter. Solids have a fixed volume and shape because their atoms are very close together and cannot move. As a result, they cannot flow or be compressed. Solids have specific properties, such as: elasticity, flexibility, fragility and strength.
Liquid
State of matter. Liquids have a fixed volume, but not a fixed shape. Their atoms are further apart and can move more freely than in solids. Liquids can flow, but cannot be compressed. Liquids have specific properties, such as: viscosity and volatility.
Gas
State of matter. Gases do not have a fixed volume or shape. Their atoms are much further apart and can move more freely than the ones of liquids. Gases can flow and be compressed.
Matter can be made up of pure substances, such as gold, or can be a mixture of different susbstances:
Pure substances
Matter is made up of substances which consist of tiny particles called atoms. Pure substances contain only one type of component which cannot be separated into other substances.
Mixtures
Type of matter that contains two or more substances. There are two types of mixtures: heretogeneous (the different components can be distinguished), and homogeneous or solutions (the different components cannot be distinguished).
There are different ways of separating the substances of a mixture, depending on the type of mixture we have:
Filtration
Method of separation of mixtures that is used to separate solids from liquids in heterogeneous mixtures.
Evaporation
Method of separation of mixtures that is used to separate solids from liquids in homogeneous mixtures. When the liquid evaporates, the solids remain.
Distillation
Method of separation of mixtures used to separate liquids that have different boiling points in homogeneous mixtures.
Decantation
Method of separation of mixtures used to separate substances of different density in heterogeneous mixtures.
Matter can change its state physically, which means the matter changes its form but the substance reimans as it was before. These are the main changes of state:
Condensation
Is a physical change of the state of matter that happens when a gas turns into a liquid.
Melting
Is a physical change of the state of matter that happens when a solid turns into a liquid.
Solidification
Is a physical change of the state of matter that happens when a liquid turns into a solid.
Evaporation
Is a physical change of the state of matter that happens when a liquid turns into a gas. If the liquid boils, it is called boiling. Evaporation is slow, while boiling happens fast when the liquid reaches a certain temperature.
Sublimation
Is a physical change of the state of matter that happens when a solid turns into a gas. When the gas turns into a solid, it is called reverse sublimation.
Also, the mater can change its state on a different way when we want to transform the substances matter contains. These are the chemical changes:
Chemical reactions
Chemical changes happen when the original matter transforms into other new substances. these changes involve chemical reactions in which atoms react and group together differently. There are many types of chemical reactions, such as:
Oxidation: It happens when some metal substances combine with oxygen in the presence of water. As a result, rust is produced.
Combustion: it happens when objects or substances are burned.
Fermentation: is a chemical reaction that happens in some living thing, such as yeast and bacteria.
All this changes, physical and chemical, need energy:
Energy
Is the ability to do work or cause change. Changes in matter require energy that can exist in different forms.
Matter has general properties, such as mass and volume, and other specific properties like density.
We can find matter in three different states:
Matter can be made up of pure substances, such as gold, or can be a mixture of different susbstances:
There are different ways of separating the substances of a mixture, depending on the type of mixture we have:
Matter can change its state physically, which means the matter changes its form but the substance reimans as it was before. These are the main changes of state:
Also, the mater can change its state on a different way when we want to transform the substances matter contains. These are the chemical changes:
All this changes, physical and chemical, need energy: